This invention relates to a labeler subsystem used in a cutting system. Such system employs sophisticated computer control to optimize the cutting sequence for optimized cutting speed and use of materials. In one typical system, using high-pressure water as the cutting medium, the system employs at least one fluid jet cutting head, or multiple heads which traverse a cutting table by movement of a carriage in one direction and cutting head movement in an orthogonal direction. The essential structure of such a system is shown in U.S. Pat. No. 3,978,748, and a more sophisticated device in copending application Ser. No. 758,368 and now U.S. Pat. No. 4,140,038, both commonly assigned with this application. Although the labeler may be used with any computerized cutter, a preferred embodiment is in a fluid jet cutting system.
The computer receives a marker as a data input indicating the maximum utilization of material within the cutting area to minimize unused material. The marker is generally prepared in advance and supplied to the cutting system as part of the overall instructions for the cutting operation to be performed. The marker essentially fits all the pieces to be cut in such a way that for a given area, material utilization is optimized. The generation of such a marker is disclosed in U.S. Pat. No. 3,887,903. The cutter system computer uses the marker as a guide for each cut to be made, and, with sensors, determines cutting tool position on the table. The cutting sequence generally begins at one end of the cutting table and proceeds across by making cuts as indicated by the marker.
As the sequence is run, at certain points, a particular cut will finish a circumferential cut about a particular piece, thereby completely severing that piece from the raw material. The cutting head may move up or down in a particular region of the cutting table making selective cuts in correspondence with marker delineations of the arrangement of pieces. The cutting head will, accordingly, selectively traverse the cutting table and, at some point, cut pieces completely about the perimeter thereof. At that point, the affixation of labels or pieces should be ideally made. The labels identify each piece. This cutting sequence is generic to many types of movable cutters, blades, laser, fluid jet and the like. The key system interface is computer control of the cutting instrument. With the interface, labeling can take place using much of the same data with deposition being a function of cutter location on the table and the required marker data.
Unfortunately, the known technology is completely devoid of any technique which is commercially acceptable for the printing and depositing of such labels in real time and without touching the cut material. Because a given marker may be used to generate well over 100 pieces in a particular cut operation, the need for identifying labels is important and should be completed as soon as possible following cutting to preclude mishandling, misplacement, etc., of unlabeled cut pieces. Conventionally, the cut sequence is totally completed, and the entire lot of cut parts is moved to an off-load station adjacent the cutting table. Labels are then manually placed on the pieces at this station. Since computer controlled cutting can proceed at a much faster rate than the corresponding placement of labels, throughput in the system lacks peak efficiency due to disparity of speeds in the respective operations. Hence, in these prior art types of operations, the cutting sequence is effectively slowed while awaiting the task of label affixation to be completed.
Another proposed solution is to provide a cover or base sheet with labels provided thereon as the top or bottom piece of a material sheet or of a stack of plies to be cut. As the cutting operation commences, these sheets are also cut so that at the end of the operation, a cover or base piece exists for each part having thereon an identifying label for part designation. While delays in throughput at the off-load end are prevented by this technique, it is still not generally satisfactory. Delays at the front or input end of the system are encountered, and the technique is acceptable for use only with single sheets or slab goods. If cutting is to be made on raw materials off rolls or reels, it is apparent that discrete cover or base sheets are not present since the goods to be cut are continuous. Hence, in those situations where roll goods are to be cut, the technique of placement of covers cannot be used. Moreover, even in the case of slab goods, problems of alignment or relative movement exist such that the labeled pieces may slide out of position, thereby making it difficult to match cut pieces with the labeled ones.
Another proposal is to use a stylus for "writing" the label on the cut piece. However, smearing of the label, ink handling and fouling of the stylus are common problems. This technique has not proven feasible since it overly complicates operations at the point of cutting.
One prior art patent is known that describes a conceptual scheme. The patent to Gerber, U.S. Pat. No. 4,028,167, shows a basic type of labeler/cutter combination actuated by computer control. The labeler is used to print a label in real time and deposit it, or a preprinted label onto a cut bundle of pattern pieces. Gerber shows a system using a knife for cutting label segments for subsequent printing, gumming and deposition on the bundle. Deposition is by way of a solenoid operated tamper to force labels from a guide bar onto the stack. However, while such systems may appear workable, in practice, considerable problems result in the transfer of labels from the labeler mechanism to the cut pieces. These problems occur because the label itself has a sticky side which should be covered or unexposed until the last possible moment in the deposition process and the labels are small and flexible, tending to jam in the system as they are transported. There is also the requirement that the cutter be stopped in order not to have the cut piece move as a result of contact with the label applicator.
Because the labeler is positioned on a moving carriage in a confined area, size must be reduced to a minimum and reliability maximized. Techniques of gumming or otherwise applying an adhesive are unacceptable, hence, pregummed labels on a waxed backing are preferred. While a take-up spool is necessary, the corresponding lack of a fluid reservoir is an acceptable trade-off. The entire sequencing is time crucial, with labels being printed and deposited at a speed commensurate with the cutting operation. The requirement of knife cutting to separate a label from the strip as shown in the Gerber patent introduces at least two problems. First, an additional mechanical step especially susceptible to incomplete operation is used. The shear knife may jam or not cut the label cleanly. Even if a clean cut is made, the label may be bent or have a fold, thereby causing a jam at the tamper. It may also result in incomplete gumming or on the wrong surface, thereby causing the label to stick on the guides or fail to stick on the piece.
Accordingly, research has continued to find a solution to the problem of real time label writing and deposition.